function combine() {
  let arr = [].concat.apply([], arguments);  //没有去重复的新数组 
  return Array.from(new Set(arr));
}

// var m = [1, 2, 2], n = [2,3,3]; 
// console.log(combine(m,n)); 



function concat1() {
  let arr2 = [].concat.call([], arguments);
  return arr2

}

var m = [1, 2, 2], n = [2, 3, 3], g = [3, 3, 4, 1, 2];
console.log(concat1(m, n, g)); 